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Telopea Vol. 6(4): 1996 
The species has anauxotelic dimorphic shoots (Fig. 4), and RGUs on both 
long-shoots and short-shoots are delimited by a period of dormancy with no 
morphological differentiation of the dormant branch-apex other than the withered 
remains of the aborted bud. The RGU of long-shoots consists of ± 3-7 metamers 
consisting of a primary leaf and associated stipules, and usually a pair (sometimes 
more) of axillary buds with perules. At the apex, the leaf-primordium and 
stipule-primordia arise separately (Fig. 5a). The stipules develop precociously 
relative to the leaf, and reach nearly adult size even before internode elongation. 
This latter takes place sometime after the fifth (usually after the sixth) plastochron. 
The terminal bud is enclosed in a series of these enlarged stipule-pairs, but the 
bud is not preformed. Axillary buds develop between the fifth and sixth 
plastochron, and apparently form in a serial file (Fig. 5c), though a third bud has 
no\ been observed to form. At most nodes buds remain dormant and the base of 
the petiole grows up around the bud-complex, sometimes nearly enclosing them 
(Fig. 5c). Branching is proleptic, apparently at nodes that have previously 
flowered. Axillary buds are of two different types. Newly formed vegetative 
buds are similar in morphology to those of Paraserianthes lophantha in that they 
consist of bract and apical region (Fig. 5b), though curiously, old ones are 
obconical and resemble those of Zapoleca telragom. After starting to develop the 
bud has an apex similar to that of the long-shoot apex, with distichous phyllotaxy. 
Likewise, though the stipules arise concomitant with the leaf-primordium, they 
develop 'much more quickly (Fig. 5d). The second type of bud is apparently 
reproductive, and its development differs from both that of the long-shoot and 
that of vegetative short-shoots in that phyllotaxy is apparently spiral, though 
this interpretation needs confirmation. Furthermore the stipules do not develop 
to any appreciable extent. Unlike the bud in Paraserianthes lophantha, the 
short-shoot in L. microphyllum grows at the apex, producing a series of reduced 
leaves, and the unit-inflorescences arise axillary to these (Fig. 6a). Fig. 6a shows 
an inflorescence arising on a sylleptically developing short-shoot. In either case 
most inflorescences develop precociously relative to the subtending leaf. 
Flowering is independent of long-shoot development, and many short-shoots bloom 
proleptically after the long-shoot has finished formation. Sometimes, though, 
unit-inflorescences develop both on short-shoots and seemingly on long-shoots, 
though in the latter on very reduced short-shoots. When in flower the inflorescence 
on some specimens resembles the pseudoraceme of capitula seen in Paraserianthes 
lophantha and Zapoteca tetragona (cf. Figs 1 and 4), but in reality they are different. 
The unit-inflorescences in the latter two species develop directly from primary buds 
concomitant with the RGU on which they form (i.e. sylleptically). In contrast, while 
the inflorescence of L. latisiliquuin may be described as a pseudoraceme of capitula 
in that there are unit-inflorescences distributed along a long-shoot, the species exhibits 
shoot-dimorphism: one type of RGU is the long-shoot that develops from the apical 
meristem, and a second type of RGU is the reproductive or vegetative short-shoot 
that develops proleptically. Following the definition of inflorescence of Grimes (1992) 
then, the disposition of flowers along the long-shoot is not the inflorescence and 
L. latisiliquiim has two kinds of inflorescences: those developing sylleptically on 
short-shoots that are subunits of an RGU, and those developing proleptically on 
short-shoots that are themselves RGUs. 
Acacia nilotica Bentham (Figs 4, 6b,c) 
Acacia nilotica is a member of subgenus Acacia, and is widespread in tropical Africa, 
through southern Asia into the Indian subcontinent. Observations were made on two 
plants cultivated by the author. As neither has bloomed, phenology has been inferred 
from herbarium specimens. 
